mech fuel pump question - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 09-23-2002, 06:43 AM
Member
 
Join Date: Sep 2002
Location: Grand Rapids, MI
Age: 35
Posts: 34
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Lightbulb mech fuel pump question

I am going from a tuneport setup to a carb setup...the new motor has a mech fuel pump. My plan is to diconnect the wiring from the elec. pump in the tank and pull the gas through the in- tank pump using the mech one.

My question is, since I already have a vent line (in-tank pump setup) , what do I do with the return line...do I leave it open as a 2nd vent line, or do I just cap it off?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 09-23-2002, 08:50 AM
bullheimer's Avatar
NEVER use credit cards!
 

Last journal entry: car with tt2's, (stockers going back on)
Last photo:
Join Date: Jan 2002
Location: North of Seattle
Posts: 2,530
Wiki Edits: 0

Thanks: 0
Thanked 5 Times in 4 Posts
Post

i dont think it would matter, but a cap would keep it clean in case you what to use it again. might want f.i. back someday, don't know,

[ September 23, 2002: Message edited by: bullheimer ]</p>
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-23-2002, 09:01 AM
New Member
 
Join Date: Nov 2001
Location: okla.city,oklahoma
Posts: 22
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

why not use the electric pump,to me it does seem like the mechanical pump will pull the fuel thru the old pump right for the car to run right,i'm trying to say enough fuel.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 09-23-2002, 09:17 AM
Member
 
Join Date: Sep 2002
Location: Grand Rapids, MI
Age: 35
Posts: 34
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

This motor is in my '95 S10 that originally had a 2.2L 4 banger in it when I bought it. I took out that motor and put in a tuneport 355, and used the electric pump in the tank. Last year I put in 377 and tried to use the elect pump with a carb, but discoverd since I was regulating the fuel from ~75psi down to 6psi, I was starving the motor for fuel at WOT, and forcing fuel past the floats . I was going to install a hi-volume, low pressure electric pump, but now I have to sell my truck (I need money for college), hence the reason I am putting the 355 back in. Since I ripped out the ECM and tuneport wires, I have decided carburate this motor, and save my tuneport for a dune truck in the future.

I used to work with a guy who put a 383 in his '91 Firebird, and had no prob pulling fuel through the elec pump, using the mech. I just don't remember what he did with the return line.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 09-23-2002, 03:38 PM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 38
Posts: 4,080
Wiki Edits: 0

Thanks: 0
Thanked 10 Times in 10 Posts
Post

given it to ya striaght, Plumb both lines into a tee fitting right where they come up into the engine compartment, then run the electric pump as you normaley would. This won't build enough pressure in the line to cause the the carb to overfill and will prevent the mechanical pump from running dry due to the restriction the in- tank pump will cause. Really it works! Been doing it for three years now.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 09-23-2002, 05:42 PM
Member
 
Join Date: Sep 2002
Location: Grand Rapids, MI
Age: 35
Posts: 34
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

So the tee works like a bypass....whatever the mech pump doesn't need, goes back to the tank??? How many psi is the pump that you are using...just curious.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 10-02-2002, 07:02 PM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 38
Posts: 4,080
Wiki Edits: 0

Thanks: 0
Thanked 10 Times in 10 Posts
Post

Ddi you get my Email?
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 10-03-2002, 07:37 AM
Member
 
Join Date: Sep 2002
Location: Grand Rapids, MI
Age: 35
Posts: 34
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

No I didn't, but your trick works great....I tried to just pull the gas through the elec pump first, but it didn't work, so I bought a brass 3/8" (tube) tee, used a reducer from 3/8" to 5/16" for the return, and put the rubber hose on cut pieces of steel brake line (threaded into the tee). Thanks for the advise, you saved me a lot of hassle by not having to drop the tank and pull the elec. pump. I would rather invest $10 in parts, than drop the tank. Thanks again.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 10-03-2002, 07:52 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 38
Posts: 4,080
Wiki Edits: 0

Thanks: 0
Thanked 10 Times in 10 Posts
Post

No problem, Although this set up works pretty well I don't think I'll be running any more than 400 HP without dropping the tank and ditching the old pump. I'd be worried about fuel starvation under nitrous use as well. Glad I could help
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 05:23 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.